Effectiveness of Emission Control Technologies for Auxiliary Engines on Ocean-Going Vessels

Abstract

Large auxiliary engines operated on ocean-going vessels in transit and at berth impact the air quality of populated areas near ports. This paper presents new information on the comparison of emission ranges from three similar engines and the effectiveness of three control technologies: switching to cleaner burning fuels, operating in the low oxides of nitrogen (NO x ) mode, and selective catalytic reduction (SCR). In-use measurements of gaseous (NO x , carbon monoxide [CO], carbon dioxide [CO 2 ]) and fine particulate matter (PM 2.5 ; total and speciated) emissions were made on three auxiliary engines on post-PanaMax class container vessels following the International Organization for Standardization-8178-1 protocol. The in-use NO x emissions for the MAN B&W 7L32/40 engine family vary from 15 to 21.1 g/kW-hr for heavy fuel oil and 8.9 to 19.6 g/kW-hr for marine distillate oil. Use of cleaner burning fuels resulted in NO x reductions ranging from 7 to 41% across different engines and a PM 2.5 reduction of up to 83%. The NO x reductions are a consequence of fuel nitrogen content and engine operation; the PM 2.5 reduction is attributed to the large reductions in the hydrated sulfate and organic carbon (OC) fractions. As expected, operating in the low-NO x mode reduced NO x emissions by approximately 32% and nearly doubled elemental carbon (EC) emissions. However, PM 2.5 emission factors were nearly unchanged because the EC emission factor is only approximately 5% of the total PM 2.5 mass. SCR reduced the NO x emission factor to less than 2.4 g/kW-hr, but it increased the PM 2.5 emissions by a factor of 1.5-3.8. This increase was a direct consequence of the conversion of sulfur dioxide to sulfate emissions on the SCR catalyst. The EC and OC fractions of PM 2.5 reduced across the SCR unit. INTRODUCTIONRecent research has shown that ship emissions are a significant contribution to the global emission inventory 1-8 and impact local and regional air quality in highly populated areas located near ports. 9 -13 Particulate matter (PM) emissions from ships have been linked to increased cardiopulmonary and lung cancer deaths across the world, most of which occur near the coastline. 14 All of these studies indicate that the forecasted increase in port activity and growth of ports will result in greater emissions from ships near coastlines and potentially a more adverse health impact for the communities located near them. Therefore, several emission control technologies are being investigated for marine engines.Ships, the largest source of port emissions, 15 generally have one main propulsion engine and three to seven auxiliary engines (AEs). AEs, typically medium-speed four-stroke marine diesel engines, are operated near/at the port to provide power for cargo refrigeration, hotelling, maneuvering, etc. Hence, AEs can have a significant impact on air quality near the ports.

On the issue of reducing the negative impact of nitrogen oxides in the system recirculation of diesel exhaust gases on applying the vortex effect

“…A system of five equations (1), (2), (5), (6) and 7contains five quantities to be determined , , , , * . In this case, the gas consumption and its heat capacity are known values.…”

“…Analysis of the main factors affecting the formation of harmful substances in diesel engines has shown that due to the peculiarities of the working process occurring in them, a decrease in emissions of incomplete combustion products, carbon oxides, hydrocarbons and harmful particles is accompanied by an increase in emissions of nitrogen oxides and by contrast [1,2,4,5,6]. Therefore, to ensure that diesel meets current and future standards for harmful emissions, exhaust gas recirculation and a catalytic method for their recovery are widely used to reduce nitrogen oxide emissions [7,8,9,10,11,12].…”

A review on regulations, current status, effects and reduction strategies of emissions for marine diesel engines

“…The results showed that the metal oxides formed by oxidation of higher concentration of metals in HFO enhanced the hydrolysis. Jayaram and Nigam [154] conducted an experiment on three auxiliary engines on container vessels and reported that SCR reduced the NOx emission factor to 1.4-2.4g/kWh which corresponded to a reduction of 90-91% for HFO and 82-84% for marine distillate oil respectively. Zhu et al [155] reported that the weighted average of NOx with low-sulfur exhaust gas was 3.08 g/kWh, lower than that of the IMO Tier III regulation while NOx with high-sulfur exhaust gas was 4.17 g/kWh, higher than that of the IMO Tier III regulation.…”

A Risk and Decision Analysis Framework to Evaluate Future PM2.5 Risk: A Case Study in Los Angeles-Long Beach Metro Area

“…There are many ocean-going vessels carrying cargo going in and out of the two ports in the Long Beach area, thus making this sector more of a concern for many people. Jayaram et al [ 51 ] illustrated that money can be spent to switch vessels to cleaner-burning fuels and operate in a lower oxide of nitrogen. For refineries, many oil refining companies are operating in the Long Beach area and money can be spent to install air cleaning and monitoring units within the factory and improve factories’ production efficiencies.…”